Adrenocorticotropic hormone (ACTH) is a linear peptide with α-melanocyte stimulating hormone (α-MSH) and corticosteroid-like mid-leaf peptides derived from pro-opiomellin precursor. ACTH contains 39 amino acids, of which 1-24 are essential amino acids that constitute biological activity, and 25-39 are protective amino acids. The 20 to 24 residues of ACTH have a negative regulation of its bioavailability and are important for the action of corticosteroid-like peptides, while corticosteroid-like peptides can inhibit N-methyl-D-aspartate. ACTH is mainly produced from the anterior pituitary, and ACTH in the middle pituitary is mainly present as an intermediate of biosynthesis. In human body, ACTH is widely distributed in many tissues such as immune cells. The distribution of ACTH in the central nervous system is also extensive.